Dataset Information

Whole Genome Sequencing and Comparative Genomics of Two Nematicidal Bacillus Strains Reveals a Wide Range of Possible Virulence Factors.

ABSTRACT: Bacillus firmus nematicidal bacterial strains are used to control plant parasitic nematode infestation of crops in agricultural production. Proteases are presumed to be the primary nematode virulence factors in nematicidal B. firmus degrading the nematode cuticle and other organs. We determined and compared the whole genome sequences of two nematicidal strains. Comparative genomics with a particular focus on possible virulence determinants revealed a wider range of possible virulence factors in a B. firmus isolate from a commercial bionematicide and a wild type Bacillus sp. isolate with nematicidal activity. The resulting 4.6 Mb B. firmus I-1582 and 5.3 Mb Bacillus sp. ZZV12-4809 genome assemblies contain respectively 18 and 19 homologs to nematode-virulent proteases, two nematode-virulent chitinase homologs in ZZV12-4809 and 28 and 36 secondary metabolite biosynthetic clusters, projected to encode antibiotics, small peptides, toxins and siderophores. The results of this study point to the genetic capability of B. firmus and related species for nematode virulence through a range of direct and indirect mechanisms.

SUBMITTER: Susic N

PROVIDER: S-EPMC7056983 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Whole Genome Sequencing and Comparative Genomics of Two Nematicidal Bacillus Strains Reveals a Wide Range of Possible Virulence Factors.

Susič Nik N Janežič Sandra S Rupnik Maja M Stare Barbara Gerič BG

G3 (Bethesda, Md.) 20200305 3

Bacillus firmus nematicidal bacterial strains are used to control plant parasitic nematode infestation of crops in agricultural production. Proteases are presumed to be the primary nematode virulence factors in nematicidal B. firmus degrading the nematode cuticle and other organs. We determined and compared the whole genome sequences of two nematicidal strains. Comparative genomics with a particular focus on possible virulence determinants revealed a wider range of possible virulen ...[more]

PMID: 31919110

Similar Datasets

Project description:BACKGROUND:Despite high vaccination coverage using acellular (ACV) and whole-cell pertussis (WCV) vaccines, the resurgence of pertussis is observed globally. Genetic divergence in circulating strains of Bordetella pertussis has been reported as one of the contributing factors for the resurgence of the disease. Our current knowledge of B. pertussis genetic evolution in circulating strains is mostly based on studies conducted in countries using ACVs targeting only a few antigens used in the production of ACVs. To better understand the adaptation to vaccine-induced selection pressure, it will be essential to study B. pertussis populations in developing countries which are using WCVs. India is a significant user and global supplier of WCVs. We report here comparative genome analyses of vaccine and clinical isolates reported from India. Whole-genome sequences obtained from vaccine strains: WCV (J445, J446, J447 and J448), ACV (BP165) were compared with Tohama-I reference strain and recently reported clinical isolates from India (BPD1, BPD2). Core genome-based phylogenetic analysis was also performed using 166 isolates reported from countries using ACV. RESULTS:Whole-genome analysis of vaccine and clinical isolates reported from India revealed high genetic similarity and conserved genome among strains. Phylogenetic analysis showed that clinical and vaccine strains share genetic closeness with reference strain Tohama-I. The allelic profile of vaccine strains (J445:ptxP1/ptxA2/prn1/fim2-1/fim3-1; J446: ptxP2/ptxA4/prn7/fim2-2/fim3-1; J447 and J448: ptxP1/ptxA1/ prn1/fim2-1/fim3-1), which matched entirely with clinical isolates (BPD1:ptxP1/ptxA1/prn1/fim2-1 and BPD2: ptxP1/ptxA1/prn1/fim2-1) reported from India. Multi-locus sequence typing (MLST) demonstrated the presence of dominant sequence types ST2 and primitive ST1 in vaccine strains which will allow better coverage against circulating strains of B. pertussis. CONCLUSIONS:The study provides a detailed characterization of vaccine and clinical strains reported from India, which will further facilitate epidemiological studies on genetic shifts in countries which are using WCVs in their immunization programs.

Project description:BackgroundListeria (L.) monocytogenes strains show a high diversity regarding stress tolerance and virulence potential. Genome studies have mainly focused on specific sequence types (STs) predominantly associated with either food or human listeriosis. This study focused on the prevalent ST155, showing equal distribution among clinical and food isolates. We evaluated the virulence potential of 20 ST155 strains and performed comparative genomic analysis of 130 ST155 strains isolated from food, food processing environments and human listeriosis cases in different countries and years.ResultsThe in vitro virulence assays using human intestinal epithelial Caco2 and hepatocytic HEPG2 cells showed an impaired virulence phenotype for six of the 20 selected ST155 strains. Genome analysis revealed no distinct clustering of strains from the same source category (food, food processing environment, and clinical isolates). All strains harbored an intact inlA and inlB locus, except four strains, which had an internal deletion in the inlA gene. All strains harbored LIPI-1, but prfA was present in a longer variant in six strains, all showing impaired virulence. The longer PrfA variant resulted in lower expression of inlA, inlB, and prfA, and no expression of hly and actA. Regarding stress-related gene content, SSI-1 was present, whereas qacH was absent in all strains. 34.6% of the strains harbored a plasmid. All but one ST155 plasmids showed high conservation and harbored cadA2, bcrABC, and a triphenylmethane reductase.ConclusionsThis study contributes to an enhanced understanding of L. monocytogenes ST155 strains, being equally distributed among isolates from humans, food, and food processing environments. The conservation of the present genetic traits and the absence of unique inherent genetic features makes these types of STs especially interesting since they are apparently equally adapted to the conditions in food processing environments, as well as in food as to the human host environment. However, a ST155-specific mutation resulting in a longer PrfA variant impaired the virulence potential of several ST155 strains.

Project description:BACKGROUND:Gardnerella vaginalis is described as a common vaginal bacterial species whose presence correlates strongly with bacterial vaginosis (BV). Here we report the genome sequencing and comparative analyses of three strains of G. vaginalis. Strains 317 (ATCC 14019) and 594 (ATCC 14018) were isolated from the vaginal tracts of women with symptomatic BV, while Strain 409-05 was isolated from a healthy, asymptomatic individual with a Nugent score of 9. PRINCIPAL FINDINGS:Substantial genomic rearrangement and heterogeneity were observed that appeared to have resulted from both mobile elements and substantial lateral gene transfer. These genomic differences translated to differences in metabolic potential. All strains are equipped with significant virulence potential, including genes encoding the previously described vaginolysin, pili for cytoadhesion, EPS biosynthetic genes for biofilm formation, and antimicrobial resistance systems, We also observed systems promoting multi-drug and lantibiotic extrusion. All G. vaginalis strains possess a large number of genes that may enhance their ability to compete with and exclude other vaginal colonists. These include up to six toxin-antitoxin systems and up to nine additional antitoxins lacking cognate toxins, several of which are clustered within each genome. All strains encode bacteriocidal toxins, including two lysozyme-like toxins produced uniquely by strain 409-05. Interestingly, the BV isolates encode numerous proteins not found in strain 409-05 that likely increase their pathogenic potential. These include enzymes enabling mucin degradation, a trait previously described to strongly correlate with BV, although commonly attributed to non-G. vaginalis species. CONCLUSIONS:Collectively, our results indicate that all three strains are able to thrive in vaginal environments, and therein the BV isolates are capable of occupying a niche that is unique from 409-05. Each strain has significant virulence potential, although genomic and metabolic differences, such as the ability to degrade mucin, indicate that the detection of G. vaginalis in the vaginal tract provides only partial information on the physiological potential of the organism.

Project description:BACKGROUND: Clostridium perfringens is a Gram-positive anaerobic bacterium causing severe diseases such as gas gangrene and pseudomembranosus colitis, that are generally due to the secretion of powerful extracellular toxins. The expression of toxin genes is mainly regulated by VirR, the response regulator of a two-component system. Up to now few targets only are known for this regulator and mainly in one strain (Strain 13). Due to the high genomic and phenotypic variability in toxin production by different strains, the development of effective strategies to counteract C. perfringens infections requires methodologies to reconstruct the VirR regulon from genome sequences. RESULTS: We implemented a two step computational strategy allowing to consider available information concerning VirR binding sites in a few species to scan all genomes of the same species, assuming the VirR targets are at least partially conserved across these strains. Results obtained are in agreement with previous works where experimental validation of the promoters have been performed and showed the presence of a core and an accessory regulon of VirR in C. perfringens strains with three target genes also located on plasmids. Moreover, the type E strain JGS1987 has the largest predicted regulon with as many as 10 VirR targets not found in the other genomes. CONCLUSIONS: In this work we exploited available experimental information concerning the targets of the VirR toxin regulator in one C. perfringens strain to obtain plausible predictions concerning target genes in genomes and plasmids of nearby strains. Our predictions are available for wet-lab researchers working on less characterized C. perfringens strains that can thus design focused experiments reducing the search space of their experiments and increasing the probability of characterizing positive targets with less efforts. Main result was that the VirR regulon is variable in different C. perfringens strains with 4 genes controlled in all but one strains and most genes controlled in one or two strains only.

Dataset Information

Whole Genome Sequencing and Comparative Genomics of Two Nematicidal Bacillus Strains Reveals a Wide Range of Possible Virulence Factors.

Publications

Whole Genome Sequencing and Comparative Genomics of Two Nematicidal <i>Bacillus</i> Strains Reveals a Wide Range of Possible Virulence Factors.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets